Transmission



5 Sheets-Sheet l TRANSMISSION o. H. BANKER man u N QQ; m h um. ww. m u m5 uw H f QM. .l w Y XN It il a B mmj D d/ E tm@ @NAN mm. uw mw IJ f Q l ,mw we i. Q. L HL l: [k Q w mwswhwmw ww Nw p u Nh. N, l Q l ,NN QQ N ,Q

Feb. 9, 1954 o, H. BANKER 2,668,453

TRANSMISSION Filed Oct. 5, 1950 I5 Sheets-Sheet 2 INVENTOR.

Feb. 9, 1954 o. H. BANKER 2,668,453

TRANSMISSION 5 Sheets-Sheet 3 lFiled Oct. 5, 1950 INVENTUR.

Patented Feb. 9, 1954 UNITED STATES` PATENT GFFICE Oscar H. Banker, Evanston, Ill., assigner to New Products Corporation, Chicago, Ill., a corporation of Delaware Application'october `5, 1950, SerialNo. 188,631

(Cl. i4-'330) Claims. l

This vinvention has to do with automotive transmissions.

One object of the invention is to provide an improved transmission in which shifting from one gear ratio to another can be accomplished without appreciable interruption in the delivery of torque by the transmission.

Another object is to provide an improved transmission wh-ich is particularly Well suited for heavy bulldozing work and can be operated rapidly back and forth between a very low or crawler forward gear ratio and a relatively fast .reverse gear ratio with .but a simple clutch manipulation and without any shifting ofgears.

Other more specific objects and advantages of the invention will be apparent to those skilled in the art upon a full understanding of 'the construction, arrangement and operation of the new transmission.

While the hydraulic clutch control features of the invention are especially applicable to dual clutches, certa'in of such features can be incorporated advantageously in single clutch transmissions and other mechanisms.

Two embodiments of the invention are presented herein by Way of explanation but it will of course be appreciated that the invention is susceptible of incorporation in other structurally modified forms coming equally within the scope of the appended claims.

In the accompanying drawings,

Fig, l is a vertical longitudinal section through ahydraulic clutch control constructed in accordance with the invention, showing the control applied to the front unit of a two-unit transmission;

Fig. 2 is a vertical longitudinal section through the rear unit of the two-unit transmission;

Fig. 3 is a vertical longitudinal section through another form of transmission equipped with the hydraulic clutch control; and y Fig. e is a fragmentary view of the rear section of the jack shaft in this transmission showing the reversing shaft which .is located at one side of the jack shaft.

The control means of the present transmission is the subject matter of my Patent No. 2,485,638 of Gctober 25, 1949. It is shown sufnciently in Fig. 1 for an understanding of the present invention as applied to the front unitv It of the variable speed transmission which is the subject of that invention. This transmission includes, in addition to the front unit I0, a rear unit II (Fig. 2) which operates in conjunction With the front unit to provide four speeds in forward and two in reverse.

The front unit AII] is adapted to be connected with the flywheel I2 of an associated motor through either one of two hydraulically operated friction clutches It and I4 (Fig. l)

The clutch i3 includes a driven clutch plate I-5 which is splined on the front end of a shaft I6, while the clutch 'I4 includes a driven clutch plate Il which is splined on the front end of a shaft I8. The driven plates I5 and Il may be of any suitable construction. The shaft I6 on which the driven plate l5 is mounted is positi'oned in axial alignment with the iiywheel I2 and is journaled at its front end in a bearing i9 carried by the flywheel (not shown). The shaft I8 on which the driven plate I'I is mounted is tubular in form and is sleeved over the shaft I5. The rear end of the shaft I8 is journaled in a bearing 20 which is mounted in a vertical partition 2l. The .partition 2l is located in a casing 22 and extends transversely of the latter. The clutches I3 and Ill and the means for controlling the operation of the same are housed in the casing 22 in front of the parti-V tion 2i, while the gearing which constitutes the front unit I5 of the transmission and the hereinafter described means for shifting the same are housed in the casing '22 behind the partition 2 I.

Complete details of the clutches and control means are illustrated and-described in my above identified Patent No. 2,485,688, hence will be but briefly referred to herein.

A sleeve 23 is xedly secured to the rear end of the shaft IB. The Afront end of the sleeve 23 is journaled in a bearing 2t which is mounted in a recessin the rear end of the shaft I8, while the rear end 'of the sleeve 23 is journaled in a bearing 25 which is mounted in a recess in the front end of a rearwardly extending shaft 2t. The shaft 26 is journaled in the casing 22 in bearings 2l and l28, in axial alignment with the c-oncentrically associated shafts I6 and I8.

An axially shiftable collar 29 is splined on the spl-eeve 23 and is provided at its rear end with a small jaw clutch 30. When the collar 2S is shifted rearwardly the clutch 3B is adapted to clutch non-rotatably within a complementary internal clutch 3l formed on the front end of the shaft 2B. The collar 2B is also provided at its front end with a relatively large gear 32. When the Icollar 29 is shifted forwardly the gear 32 is adapted to mesh with a reversing idler gear 33, which reversing gear is mounted on a shaft (not shown) and is arranged in constant mesh with .a gear 34 formed on an elongated hub 35. The hub 35 is journaled on a shaft 36 which is xedly mounted at its front end in the partition 2| and at its rear end in the rear wall of the casing 22. rIhe hub 35 is provided at its rear end with a second gear 31 which meshes with a gear 38 formed on the front end of the shaft 25.

From the foregoing it will be understood that when the collar 29 is shifted rearwardly from its neutral position (shown in Fig. 1) it will connect the shaft I6 directly with the shaft 26 through the clutch-like coupling 30-3 I, and that when the collar 29 is shifted forwardly from its neutral position it will connect-,said shafts together in reverse under a multiplication of torque through the gears 32, 33, 34, 31 and 33.

The collar 29 is adapted to be shifted either forwardly or rearwardly from its neutral position by means of a shifting yoke 39. The yoke 39 engages within a groove 40 in the collar 29 and is slidably mounted on a rod 4| located Within the casing 22. The yoke is shifted from a point eXteriorly of the casing by a transversely disposed rock shaft 42, which shaft is provided on the inside of the casing with a short lever arm 43 which is pivotally connected at its free upper end with the yoke 39 by a pin 44. The yoke 39 is yieldably indexed in its neutral, reverse and forward positions by a spring pressed detent 45 which is carried by the yoke and engages within annular positioning grooves 46, 41 and 48 formed in the surface of the rod 4 I.

The tubular shaft I8 is provided at its rear end with a gear 49 which meshes with a gear 50 formed on the front end of the previously mentioned hub 35. This connection enables the shaft I8 to drive the shaft 26 in a forward direction through the low gear ratio provided by the gears 49, 50, 31 and 3B.

The driven clutch plates I and I1 of the clutches I3 and I4 are located in a circular recess 5| which is formed in the rear face of the flywheel I2. The recess 5I is closed at its rear end by a centrally apertured cover plate 52 which is secured by screws 53 to the outer periphery of the flywheel. An annular casing 54 is secured by screws 55 to the inner periphery of the cover plate 52 and extends rearwardly about the shaft I8 to a point adjacent the partition 2|. The rear end 56 of the casing 54 is reduced in diameter and fits snugly but rotatably within a second stationary casing 51 which is secured at its rear end to the partition 2 I.

The casing 54 contains two sets of forwardly opening hydraulic cylinders 59, which cylinders are of substantial axial length and arranged in a circle in equally spaced relation to each other. The cylinders are divided into two sets, preferably of three cylinders each, with the cylinders in one set alternating with the cylinders in the other set. The cylinders 59 contain closely f1tting pistons 59 which are provided with cupshaped packings 6|. The pistons in one set of the cylinders 59 engage with the inner ends of certain levers 63 which operate the clutch I4, while the pistons in the other set of cylinders (not shown) engage with the inner ends of another set of levers (not shown) which operate the clutch i3. In the neutral position of the dual clutch mechanism (see Fig. 1) all of the pistons 69 are disposed at approximately their half-way points in the respective sets of cylinders.

The two sets of levers, which extend into the front ends of the cylinders through slots in the outer sides of the latter, operate the clutches I3 and I4 through an annular pressure plate 4 64, which pressure plate is located between the clutch plates I5 and I1 in the recess 5I in the flywheel I2. The pressure plate 64 is shiftable axially but is held against rotation relative to the ywheel by two sets of studs 56 on the outer periphery of the pressure plate, which studs project rearwardly through circumferentially interlocking apertures in the cover plate 52. The studs 66 in one of the sets referred to coact with the levers 63 of one set of levers, while the studs in the other set coact respectively with the other set of levers 63. In the neutral position of the dual clutch mechanism the pressure plate 64 is maintained free from frictional engagement with both of the clutch plates I5 and I1 by an equalizing means which is generally designated 61. These means, as well as other details of the hydraulic clutch control mechanism, are fully described in my patent identified above, to which reference may be made for further details. It suffices to state that the respective sets of levers 63 are fulcrumed and operatively connected to pressure plate E4 and pistons 69 in such manner that one thereof is actuated to shift the pressure plate and engage clutch I3 when one set of cylinders 59 is pressurized, while the other set of levers is actuated to shift plate 64 in the opposite direction and thus engage clutch I4, when the other set of cylinders is pressurized.

A hydraulic pump and single valve arrangement by which the respective sets of cylinders are selectively pressurized is also fully disclosed and described in Patent 2,485,688, hence further reference thereto is omitted here.

Passing to the rear unit II of the transmissionwhich unit may be used in conjunction with the front unit IU-this unit is mounted in a separate casing |26 (see Fig. 2). It includes an upper shaft |21 which is jcurnaled adjacent its front end in a bearing |28 and adjacent its rear end in a bearing |29. The shaft |21 is arranged in axial alignment with the output shaft 26 of the front unit I6 and is connected directly with the latter, preferably by a flexible coupling |39. A small gear I3I is secured to the front portion of the shaft |21, and a relatively large gear |32 is secured to the rear portion of the shaft |21.

Another shaft |33 is located in the casing |26, below and parallel to the shaft |21. This lower shaft is journaled at its front end in a bearing |34 and is journaled adjacent its rear end in a bearing |35. The rear end of the shaft |33 is provided with a beveled pinion |36 which meshes laterally with a relatively large bevel gear (not shown) connected with the load. A sleeve |31 is secured to the shaft |33 and is provided intermediate its ends with an annular enlargement |38 having radially projecting clutch teeth |39. A collar |40 having complementary clutch teeth I4| on its inner periphery is mounted on the enlargement |38 for axially shiftable but nonrotatable engagement with the same.

A relatively large gear |42 is journaled on the front portion of the sleeve |31, in mesh with the gear |3| on the shaft I2l. The gear |42 is provided adjacent the enlargement |38 with radially projecting clutch teeth |43 of the same size and spacing as the teeth |39 on the sleeve |31. When the collar |40 is shifted forwardly from its neutral position (shown in Fig. 2) the teeth |4| on the inside of the collar will bridge the teeth I 39 and |43 and will clutch the gear |42 to the shaft |33.

A second relatively small gear |44 is journaled on the rear portion of the sleeve |31 in mesh with the gear |32 on the shaft 121. -The gear |414 is also provided with v-radially projecting clutch teeth |45. When the collar I 40 is shifted rear Wardly from its neutralpositionthe teeth .i at will bridge the teeth 4|39 and |45 and will :clutch Athe gear 44 totheshaft |33.

The collar |40 can `be shifted axially from its neutral position into .either its forward position or vits Vrearward position by a swinging yoke |46 which is secured to va rock `shaft |41 journaled in one side yof the casing I 26. The shaft |41 extends to the outside of the casing and is `prof vided there with an operating lever (not shown). The yoke |46 vis indexed in each vof its three diierent operating positions by means of an exteriorly accessible spring Vpressed plunger |48 which is mounted in the casing and projects in- Wardly into resiliently yieldable engagement with centering recesses |49, A|50 vand 15| formed in an -opposing :portion of the yoke |46.

The upper shaft |21 may be provided, if desired, with a power take-off shaft |52. This shaft, which may be used for any purpose desired, is releasably connected with the rear end of the shaft |21 by an axially shiftable clutch collar assembly |53.

The hydraulic dual clutch assembly shown and described, employing `a single automatically centralized lpressure-plate for both clutches, actuated by two oppositely moving sets yof pistons, and controlled by a single fluid directing valve, permits the .associated transmission lto be shifted instantlyfrom ,one gear to another, without loss of torque. For bulldozing work, for which the dual clutch control is well suitedfthe SearlatiOS in the transmission are Dreierabl-yso constructed as to give a faster speed in vreverse than in lowv low forward. When .the collar 29 is moved forwardly into its :reversing position actuation of. the clutch I4 will drive the ytransrrlis sich for- :wardlr at; a 'Very' slow crawler Speed Yunder a high multiplication of torque, and actuation vof the clutch I3 will drive the transmission rearwardly at a relatively fast speed` This enables kthe operator, by merely alternating the position of the control valve, to. make short quickly repeated advances against the Amaterial or .obstruction being wcrled on.

It will be noted :that 'the various shafts in the transmission are so mounted in their bearings as to effect av'iloating arrangement .of the same.

This arrangement in, large measure eliminates strains -fwithin the transmission resulting ,from wading and heating, facilitates assembling `.and disassembling, andv reduces vproduction costs. The shaft I6 is supported at its rear .end in the sleeve 2?., while the concentrically associated tubular shaft I3 supports the front end Qf the sleeve 2-3 and is in turn supported in the vertical partition `2l of the casine.- Of the two bear-ings Supporting; each shaft. one is fixed. against axial movement while the other is capable ci Some axial movement, whereby to compensate for end Wise expansion and .contraction of the shafts. For the shaft le, for instance, the bearing 25 is fixed while the bearing i9 is shiftable :axially relative to the shaft; for the shaft |84, the. bear.- ing 2|) is fixed while the bear-ing 24 is shiftable; and for the shaft 26, the bearing 21 is fixed while the bearing 23 is shiftable. The same is true The lowest ferward Agear Vratio -will `be obtained 'byxletting clutch I4, with the shifting collar -29 in its rear. wardly clutched position .and the shifting collar |40 in its forwardly clutched position. .Second is yimmediately obtained vby .letting in clutch I3, with collar 29 still in its rearwardly clutched position. Third `is then obtained by momentarily neutralizing clutch I3, shifting collar |40 into its rearwardly clutched position, and letting in clutch I4. yFourth is kthen obtained by letting in clutch I3. It `will of course be Y.understood that any `suitable vgear shifting linkage can be connected up with the shifting devices 39 yand 14.6 under the control of a single lever to properly coordinate the operation of those devices,

Infiss. 3 and 4.a mod-ined single unit multiple speed transmission of novel construction is shown. This transmission is equipped with va hydraulicallT Operated dual clutch control of the saine construction as that illustrated in Fig. 1. Only the clutch driven plates |54 and |55 of the two clutches Aare shown in connection with this structure, the `other parts being omitted for clearness. This modified transmission is housed within a casing |56. The driven plate I 54 -is shiftably -splined Vto the front -end of a shaft |51, While the driven plate |55 is shiftably splined to the front end of a tubular shaft |58 which surrounds Ytheshaft |51.

The tubular shaft .|58 Vextends rearwardly into a second tubular shaft |59 and -is iixedly splined to that shaft. The shaft |59 is provided adjacent its front end with a small .integral ygear .|66 and .is .provided adjacent its rear end rwith a relatively large integral v.gear |61. The front end of the shaft |59 is journaled in a bearing |52 which is rnounted the front wall |63 of the casing |56, while the rear .end of the shaft |59 i5 journaled in a .bearing |64 which is mounted in a vertical web formed in the casing.

A third tubulary shaft |66 extends rearwardly .from .the shaft |59. The front end of the shaft |55 is journaled in a bearing |61 which is vvmounted inthe hollow rear end. of the shaft |59, while the rear end of theshaft |616 iS jOurnaled in. a bearing |63 which is mounted in another vertical web |69. The shaft .|51 terminates in the shaft ,|66 adjacent the rear end of the latter and is .xedly splined to the same. A large gear .Ile of `somewhat larger size than `the gear IBI is journaled' on the shaft |66 near vthe rear end of .the latter, and a Vsleeve I1| is keyed to the shaft les in Ifront of the gear |10. The sleeve ,I 1I is provided with an annular enlargement |12 having radially projecting clutch, teeth |13. An axially shiftable clutch collar |14 having complementary teeth |15 on its inner periphery is sleeved over the enlargement 4|12 in circumfeientially interloked engagement with the. latter. The gear 15 is provided adjacent theenlargement |12 with radially projecting teeth `|16 of the same Size and Vspacing as the teeth .|13 on 4the enlargement. When the clutch collar |13 is shifted rearwardly from its neutral position (shown in Eg. 3,) the teeth |15 on the vinside oi the same will bridge the teeth |13 and |16, clutching @he gear |15) vto the ,shaft |56. A relatively ,small gear |11 of somewhat larger size than the gear |66 is journaled .on the, sleeve .|171 in front et the enlargement |11 and is provided adjacent the enlargement with radially proicting teeth .|18 of the Same sizevand spacing as the teeth |13 and |16. When the clutch collar |14 is shiftedy forwardly ,from its neutral posi.- tion the teeth |15 on-'the inside4 of the same 7 will bridge the teeth |13 and |18, clutching the gear |11 to the shaft |66.

A shaft |19-which constitutes the output shaft of the transmission-extends rearwardly from the third tubular shaft |66. The front end of the shaft |19 is journaled in a bearing |80 which is mounted in the hollow rear end of the shaft |66, while the rear end of the shaft |19 is journaled in a bearing I8| which is mounted in the rear wall |82 of the casing. A large gear l|83 is shiftably splined on the shaft |19 and is provided with a forwardly extending hub |84 having radially projecting clutch teeth |85. The hollow rear end of the shaft |66 is enlarged and formed into a rearwardly extending annular fiange |86. The flange |86 is provided on its innerperiphery with clutch teeth |81 which are complementary to the clutch teeth |85 on the hub |84 of the gear |83. When the gear |83 is shifted forwardly along the shaft |19 the teeth |85 will interlock circumferentially with the teeth |81, clutching the shaft |19 directly to the shaft |66,

The two gears |60 and IBI on the tubular shaft |59 mesh respectively with two gears |88 and |89 which are journaled below the gears |60 and I6| on a sleeve |90. The sleeve |99 is xedly splined to a jack shaft |9|. The front end of the shaft |9| is journaled in a bearing |92 which is mounted in the lower portion of the front wall |63 of the casing, while the rear end of the shaft |9| is journaled in a bearing |93 which is mounted in the lower portion of the vertical web |65. y

The sleeve |90 is provided intermediate the gears |88 and |89 with an annular enlargement |94 having radially projecting clutch teeth |95, and the hubs of the gears |88 and |89 are provided with similar clutch teeth |96 and |91. An axially shiftable clutch collar |98 having complementary teeth |99 on its inner periphery is sleeved over the enlargement |94 in circumferentially interlocked engagement with the latter. When shifted forwardly from its neutral position the collar |98 clutches the gear |88 to the shaft I9 I, and when shifted rearwardly from its neutral position it clutches the gear |89 to the shaft |9|.

A second jack shaft 200 extends rearwardly from the shaft |9|. The rear end of the shaft |9| contains a pilot recess 20| and the front end of the shaft 200 is provided with a ball tip 202 which is supported in the recess 20|. The rear end of the shaft 200 is journaled in a bearing 293 which is mounted in the lower portion of the rear wall |82 of the casing. The gear |11 meshes downwardly with a gear 204 which is keyed to the shaft 200. The gear 204 is also connected with a radial flange 205 on the rear end of the shaft |9| by means of an axially separable but circumferentially interlocking spline connection 206.

The shaft 200 is provided with three integrally formed gears 201, 208 and 209 of progressively smaller size. The gear meshes downwardly with the gear 201. The gear 209 meshes upwardly with the gear |83 when the latter is shifted rearwardly into the plane of the gear 209. The gear 208 meshes laterally with a reversing gear 2|0 (see Fig. 4) which is secured to the front end of a short countershaft 2| The shaft 2| is journaled in the casing at one side of the shaft 200.' A gear 2|2 is shiftably splined on the shaft 2| I. When the gear 2|2 is shifted rearwardly into the plane of the gear |83, in the forwardly disconnected position of the latter, it

will mesh with the gear |83 and establislr'a reverse drive between the shaft 200 and the shaft |19.

As in the transmission first described, the bearings in which the various shafts are mounted are so constructed and arranged as to compensate effectively for the endwise expansion and contraction occasioned by heating and load transmitting conditions. The shafts |51 and |58 are oatingly mounted relative to each other. The inner bearing for the rear end of the sleeve |66 in which the shaft |51 is splined is shiftable axially between the sleeve and the shaft |19, and the inner bearing |61 for the rear end of the sleeve |59 in which the shaft |58 is secured is likewise shiftable axially between that sleeve and the sleeve |66. The end bearings |62 and |8| are xed in the casing, while the intermediate bearings |64 and |68, although xed with respect to the casing are shiftable with respect to the sleeves |59 and |66. The same is true of the bearings for the lower shaft sections 9| and 200. The bearing |92 for the front section |9| is fixed while the bearing |93 for that section is shiftable relative to the casing. Likewise, the bearing 203 for the rear section 200 is fixed while the pilot bearing 202 is shiftable.

The universal drive connection effected between the two shaft sections |9| and 200 by the introduction of the pilot bearing 202 and the separable clutch 206 permits of the intermediate bearing support |93 without setting up any bearing stresses and greatly facilitates manufacture and assembly.

What I claim is:

1.V In a multiple speed transmission, two concentrically arranged driving shafts, selectively controlled means for driving one or the other of the driving shafts, a driven shaft positioned in axial alignment with the driving shafts, means for selectively connecting one of the driving shafts for selectively connecting the same to the driven shaft either directly or in reverse, and means for connecting the other driving shaft to the driven shaft under a reduction, said rst named means comprising a sleeve secured to and surrounding the inner driving shaft and journaled at axially spaced points by the outer driving shaft and driven shaft respectively.

2. In a multiple speed transmission, two concentrically arranged driving shafts, selectively controlled means for driving one or the other of the driving shafts, a driven shaft positioned in axial alignment with the driving shafts, means for selectively connecting one of the driving shafts to the driven shaft either directly or in reverse, and means for connecting the other driving shaft to the driven shaft under a reduction, said first named means comprising a sleeve secured to and surrounding the inner driving shaft and internally journaled at its opposite ends in the outer driving shaft and driven shaft respectively.

3. In a multiple speed transmission, two cencentrically arranged driving shafts, selectively controlled means for driving one or the other of the driving shafts, a driven shaft positioned in axial alignment with the driving shafts, means for selectively connecting one of the driving shafts to the driven shaft either directly or in reverse, and means for connecting the other driving shaft to the driven shaft under a reduction, said rst named means comprising a sleeve secured to the inner driving shaft and supporting the same for rotation, and bearings rotatively journaling said sleeve at axially spaced points on the outer driving shaft and driven shaft respectively, at least one of said bearings being an axially shiftable one, a reverse driving unit, a member splined on said sleeve and provided with elements selectively engageable with said driven shaft and reverse driving unit respectively to drive the same, yand means to shift said member axially on said sleeve for said respective selective engagements. Y

4. In a multiple speed transmission, two concentrically arranged driving shafts, selectivelyT controlled means for driving one or the other of the driving shafts, a driven shaft positioned in axial alignment with the driving shafts, means for selectively connecting one of the driving shafts to the driven shaft either directly or in reverse, and means for connecting the other driving shaft to the driven shaft under a reduction, said first named means comprising a sleeve secured to the inner driving shaft, and bearings rotatively journaling said sleeve at axially spaced points on the outer driving shaft and driven shaft respectively, a reverse driving unit, a member splined on said sleeve and provided with elements selectively engageable with said driven shaft and reverse driving unit respectively to drive the same, and means to shift said member axially on Isaid sleeve for said respective selective engagements.

5. In a multiple speed dual clutch transmission, two selectively operable clutches, two concentrically associated driving shafts connected at their front ends with said clutches, a driven shaft in axial alignment with the driving shafts, a collar in rotatively fixed, axially slidable relation to the rear end of the inner driving shaft, a clutch associated with the collar for connecting the inner driving shaft to the driven shaft in a 1:1 drive when the collar is shifted rearwardly, a gear on the front end of the driven shaft, a countershaft, a gear on the countershaft in mesh with the gear on the driven shaft, two other gears on the countershaft, a gear associated with the collar for rotating one of the two last mentioned gears in reverse when the collar is shifted forwardly, whereby to drive the driven shaft in reverse, and a gear on the rear end of the outer driving shaft in mesh with the remaining gear on the countershaft for driving the driven shaft forwardly under a multiplication of torque.

6. A multiple speed transmission comprising two concentrically arranged driving shafts, two friction clutches operatively connected to said shafts for selectively coupling one or the other thereof with an associated rotary device, a driven shaft positioned in axial alignment with said driving shafts, gears fixed on said driven shaft and one of the driving shafts, countershaft gears including a reversing gear and gears in constant mesh with said respective driven and driving shaft gears, a reversing idler gear meshing with said countershaft reversing gear, and a selector gear in concentric, rotatively fixed relation to the other driving shaft, said selector gear being axially shiftable relative to said last named shaft for meshing engagement with said idler gear and being provided with means to drivingly engage said driven shaft gear upon axial shifting relative to the latter.

7. A multiple speed transmission comprising two concentrically arranged driving shafts, two friction clutches operatively connected to said shafts for selectively coupling one or the other thereof with an associated rotary device, a driven shaft positioned in axial alignment with said driving shafts, gears fixed on said driven shaft and the outer driving shaft, countershaft gears including a reversing gear and gears in constant mesh with said respective driven and driving shaft gears, a reversing idler gear meshing with said countershaft reversing gear, and a selector gear in concentric rotatively fixed relation to the inner driving shaft, said selector gear being axially shiftable relative to said last named shaft for meshing engagement with said idler gear and being provided with means to drivingly engage said driven shaft gear upon axial shifting relative to the latter.

8. A multiple speed transmission comprising two concentrically arranged driving shafts, two friction clutches operatively connected to said shafts for selectively coupling one or the other thereof with an associated rotary device, a driven shaft positioned in axial alignment with said driving shafts, gears fixed on said driven shaft and one of the driving shafts, countershaft gears including a reversing gear and gears in constant mesh with said respective driven and driving shaft gears, a reversing idler gear meshing with said countershaft reversing gear, and a selector gear in concentric rotatively fixed relation to the other driving shaft, said selector gear being axially shiftable relative to said last named shaft for meshing engagement with said idler gear and being provided with means to drivingly engage said driven shaft gear upon axial shifting relative to the latter, the pitch diameter of the countershaft gear meshing with said first named driving shaft gear exceeding that of said countershaft reversing gear, whereby selective operation of said clutches when said reversing idler gear is driven will rotate said driven shaft forwardly at slow speed and multiplied torque or backwardly at greater speed and less torque.

9. A transmission in accordance with claim 7 in which said inner driving shaft has a sleeve fixed thereon on which said selector gear is mounted for relatively non-rotative axial sliding movement.

10. A transmission in accordance with claim 7 in which said inner driving shaft has a sleeve fixed thereon on which said selector gear is mounted for relatively non-rotative, axial sliding movement, said sleeve being journalled for rotation by said outer driving shaft and said driven shafts, respectively.

OSCAR H. BANKER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,705,032 Short Mar. 12, 1929 2,098,716 Budlong Nov. 9, 1937 2,174,259 Feerick et al Sept. 26, 1939 2,232,159 Blood Feb. 18, 1941 2,386,541 Campodonico Oct. 9, 1945 2,599,801 Youngren et al. June 10, 1952 

